Electromechanical commutator with rolling contact-type structure



Jan. 28, 1964 w. R. WILSON 3,119,907

ELECTRO HANICAL O MUTATOR WITH ROLLING v ONTACT- E STRUCTURE Filed Dec. 50, 1960 4 Sheets-Sheet 1 O V r V V Z i /5 20 INVENTOR a /0 23 ATTORNEYS Jan. 28, 1964 w. R. WILSON 3,119,907

ELECTROMEC NICAL c ATO TH ROLLING TOR Wblh'azm WbZson Mam ATTORNEYS Jan. 28, 1964 w. R. WILSON 3,119,907

ELECTROMECHANICAL COMMUTATOR WITH ROLLING 1 CONTACT-TYPE STRUCTURE I Filed Dec. 50, 1960 4 Sheets-Sheet 3 INVENTQR Wa'zlam R. Wilson ATTORNEYS Jan. 28, 1964 w. R. WILSON 3,119,907

ELECTROMECHANICAL COMMUTATOR WITH ROLLING CONTACT-TYPE STRUCTURE Filed Dec. 30, 1960 4 Sheets-Sheet 4 m0 ma I VENTOR #3 l VzZZmm R. 580

ORNEYS United States Patent 3,119,907 ELECTRGMECHANHCAL COMMUTATOR WITH RULLHNG CONTACT-TYPE STRUCTURE William R. Wilson, Dallas, Tern, assignor to Texas linstruments incorporated, Dallas, Tern, a corporation of Delaware Filed Dec. 39, F569, Ser- No. 7%,755 Claims. (Cl. 200-24) This invention relates to commutators, and more particularly to a novel mechanical commutator which utilizes a rolling contact-type structure.

in prior mechanical commutators, sliding contacts have been utilized to sample a plurality of conductors in time sequence. However, the use of sliding contacts entails certain disadvantages and drawbacks. The contacts wear in a short time because their surfaces are continuously rubbing against the surfaces of the conductors. Furthermore, as the contacts wear, poor electrical connections exist between the conductors and the contacts, and cause noise in the system. In the past, spring loaded contacts had to be used to maintain the proper tension on the sliding contacts to insure a good electrical conection. These disadvantages and drawbacks have made mechanical commutators utilizing sliding contacts incompatible with high signal quality systems.

To overcome these drawbacks the art has turned to electronic commutators to obtain good signal quality. This, despite the fact that electronic commutators are much more expensive than mechanical ones.

It is, therefore, the principal aim of this invention to provide a novel mechanical commutator which eliminates the aforementioned disadvantages and drawbacks, whereby it can be used in a high signal quality system and thereby result in substantial savings in cost of equipment. This is accomplished by the present invention by providing a novel mechanical commutator which utilizes a rolling contact type structure. This novel commutator structure is comprised of conducting rotatable elements, such as balls or rollers, held in a race defined by a conducting collector shaft and a non-conducting ring. The conducting collector shaft is freely rotatable or is rotated by appropriate drive means. it is preferred to keep the nonconducting ring stationary. A plurality of conductors are embedded in the non-conducting ring and distributed around its inner periphery. In one specific embodiment conducting rollers and the conducting collector shaft are laminated to obtain a multiple channel commutator. The conducting balls or rollers can be rotatably mounted on studs attached to a disk driven by a gear. The rotatably mounted balls or rollers and the freely rotatable collector shaft rotate together due to an interference or frictional fit. The rotated conducting balls or rollers move and sample the imbedded conductors in time sequence. The surfaces of the balls or rollers make rolling contact with the surfaces of the imbedded conductors. Thus, this novel rolling-contact type structure for a mechanical commutator eliminates the disadvantages and drawbacks which characterized the prior known sliding action mechanical commutators.

It is, therefore, the principal aim of this invention to provide a novel commutator which utilizes a rollingcontact type structure.

Another object of this invention is to provide a novel structure for a mechanical commutator which utilizes balls or rollers to obtain a rolling contact.

A further object of this invention is to provide a novel mechanical commutator which has substantially better signal quality than mechanical commutators heretofore known.

A still further object of this invention is to provide a novel multi-channel mechanical commutator.

"'ice Another object of this invention is to provide a novel structure for a mechanical commutator which is capable of performing as well as electronic commutators, but which can be fabricated at a substantially reduced cost.

Other and further objects and advantages of the present invention will become readily apparent from the following detailed description of a preferred embodiment of the invention when taken in conjunction with the appended drawings in which:

FIGURE 1 is a transverse sectional view of a preferred embodiment of the present invention;

FIGURE la is a transverse view of a preferred embodiment of the present invention which illustrates the sampling sequence;

FIGURE 2 is a longitudinal sectional view taken along line 2-2 of FIGURE 1;

FIGURE 3 is a longitudinal sectional view of an alternative embodiment of the present invention;

FIGURE 4 is a transverse sectional view of another alternative embodiment of the present invention; and

FIGURE 5 is a longitudinal sectional view taken along line 5-5 of FIGURE 4.

Referring now to FIGURES l and 2 wherein like numerals have been used to designate like parts and which illustrate the sampling sequence, there is shown a novel mechanical commutator embodying the principles of this invention. The commutator is comprised of conducting balls 5 held in a race defined by a freely rotatable conducting collector shaft 6 and a stationary nonconduc ing ring 7. The shaft 6, balls 5 and ring 7 are concentrically positioned. The halls are made of a physically strorn metal and preferably coated with a noble metal, although another suitable high conductivity metal can be used. An inner ball race it is formed on the surface of the freely rotatably conducting collector shaft 6, and an outer ball race 9 is formed on the inner surface of the stationary nonconducting ring '7. The collector shaft 6 is made of a conducting metal, such as copper or brass. The nonconducting ring '7 can be made of hard plastic, such as an epoxy resin or any other suitable nonconductor, which would include ceramic and glass materials along with many others. A screw 13 can be used to mount the nonconducting ring '7 to a stationary bracket 1%.

A plurality of conductors il with conductor leads 12 connected thereto are embedded in the stationary nonconducting ring 7. The conductors 11 are distributed around the inner periphery of the nonconducting ring. For simplicity, FIGURE 1 shows conductors Ill with leads 12 connected thereto embedded in only a portion of the nonconducting ring '7. Each conductor lead 12 can be connected to an incoming information channel. The surface of the conductors 1]. follows the contour of the outer ball race 9 to ensure a good electrical connection between the conductors ill and the balls 5. The conductors 11 are made of gold or any other suitable conducting material.

The conducting collector shaft 6 defines a pair of inner races l and 2 axially spaced to the right of race 8 as viewed in FIGURE 2. Ball bearings 14 are positioned in the races l and 2 and a stationary conducting ring 15 encompasses the balls 14 and shaft 6. Balls 14 are also received in outer races 3 and 4 defined by the inner peripheral surface of the ring 15. The conducting ring 15 is made stationary by attaching it to the bracket 16. The bracket 16 is made stationary by any conventional means. An insulating layer 17 is interposed between ring 15 and bracket 16 to isolate these elements electrically. A single take-off conductor 1) is connected to conducting ring 15 by means of screw 18.

Each of the conducting balls 5, which are positioned in races h and 9, has a hole or bore extending completely through the ball. The left ends of insulator studs 3 Zll as viewed in FIGURE 2, are inserted in the holes in balls 5 to mount them for rotation. An annulus 21 in spaced axially from the stationary nonconducting ring '7, and encompasses the freely rotatable conducting collector shaft 6. The annulus Ell which is radially spaced, as indicated by reference numeral 125, from the shaft 6 and, therefore, electrically isolated, has holes arranged in a circular pattern located in the face of the annulus 21.

The right ends of the insulator studs Eli are inserted in the holes in the annulus 21. A collar 22 is mounted on each stud 2t? and is located between the respective balls 5 and annulus 2-1. The collars .22 have a larger diameter than the holes in the balls 5 to prevent the insulator studs 2% from sliding out of the holes in the annulus 21. The base portion of the annulus 21 has an enlarged diameter and defines gear teeth 24 on its periphery to mesh with spur gear 23 which is driven by any suitable means, such as a small electric motor via shaft 126.

When the annulus 21 is rotated by spur gears 23, the rotatably mounted balls 5 and freely rotatable collector shaft 6 rotate due to the interference or frictional fit. The rotating conducting balls 5 move and sample the embedded conductors 11 on stationary ring '7 in time sequence. The surfaces of the rotating balls 5 make rolling contact with the surfaces of the embedded conductors Ill. The balls 5 are rotatably mounted on insulator studs 2% and attached to the annulus Zll to ensure that they are maintained in proper spatial relationship, so that each ball will make contact with only one of the conductors at any one moment. The speed at which balls 5 are driven can be controlled by governing the motor driving spur gear 23 to ensure proper sampling rate between the rotating balls 5' and the embedded conductors ll. Thus, the information present on the conductors 11 as electrical signals is sampled by the balls 5 in sequence, and transmitted via collector shaft 6, balls 14 and ring 15 to take-off conductor 19.

It will be appreciated that the apparatus can-be modifled so that the conducting balls 5 are not driven directly. If gear 23 was disengaged from gear teeth 24 and meshed with an insulated ring gear fixed to collector shaft 6, then collector shaft 6 could be driven by appropriate means applied to gear 23. This would cause the balls to rotate due to the interference or frictional fit. It will also be appreciated that any suitable means can still be used to remove the electrical information from the collector shaft 6. Moreover, the annulus 21 and its related parts could be eliminated.

The manner by which is determined the spacing of the contacts, number of balls and size of balls will now be discussed with reference to FIGURE 1a. In the field of telemetry, it has become standard practice to utilize commutators for sampling and collecting data at various intervals. The usual commutator practice is to utilize one of three types which are referred to as thirty-thirty (thirty channels sampled thirty times per second), fortyfivetwenty (fortyfive channels sampled twenty times per second), and ninety-ten (ninety channels sampled ten times per second). It will be observed that in this general commutator practice, 960 data samples are taken per second from 30, 45 or 90 channels.

In the present invention, the standard telemetry prac- 'ce concerning commutators is observed as will be realized by the specific embodiment of a 4520 type system. The present invention can utilize all three of the heretofore men ioned systems. However, it is necessary in the -30 and -20 to utilize an odd number of balls Whereas it is necessary to utilize an even number of balls in the 9040 system. Obviously, if these standard practices in commutator systems are not maintained, innumerable combinations of balls can be utilized within the broad concept of the present invention.

Momentarily considering FIGURE 1, it is obser ed that it illustrates seven balls 5 located within an inner and outer race, and there are partially illustrated several contacts 11 surrounding the inner periphery of the outer race or ring. In considering the 4520 system as a specific embodiment of present invention, the number of contacts ll. located on the inner periphery of nonconducting ring 7 numbers 45 it is essential to maintain the standard commutator practice that each of the 45 channels or conductors 11 must be electrically contacted 20 times per second to obtain 900 data samples per second. From the above, it will be understood that to maintain this standard time sampling, it is necessary to make a contact every 1,111 microseconds. it is this contact rate which determines the diameter of the collector shaft 6 and the diameter of the balls 5 so as to have an appropriate ratio to maintain the desired standard rate for sampling. It should be appreciated that the collector shaft and the diameter of the balls could be varied so that high speed or low speed motors could be utilized to either vary the contact rate or maintain a highly accurate rate. The one feature which should be kept in mind by those skilled in the art in selecting appropriate ratios to maintain the proper contact timing is that rolling contact must be maintained at all times, which inherently requires a frictional fit between the collector shaft 6 and the inner periphery of the ring contact 7.

Referring to FIGURE la which illustrates all of the 45 conductors, the sequence contacting the different conductors ltllll through 1645 of the specific embodiment occurs as follows. Considering the ball Ztil in FIGURE In, it is illustrated as making contact with conductor 1W1. Since all the balls are rotated concurrently, as the ball Still, for example, rotates of the angular distance beween contact itlill and M08, ball 2&3 would make contact With conductor M3432 and, in the next rotation between the angular distance of conductor ltlilll and Wild, ball 265 would contact conductor 1W3. Following this same angular rotational sequence, when ball 2%, along With the rest of the balls, has moved angularly of 360 or 8, ball Zilll will then make contact with conductor M93. It will be noted that, in this sequence of events, every other ball is sequentially making appropriate numerical contact; for instance, ball Ziill makes contact with conductor llldl, 2&3 makes contact with conductor 10552, 2W5 makes contact with conductor 1633, 297 makes contact with conductor little, 2% makes contact with conductor 1M5, 264 makes contact with conductor lllllo, and ball 2% makes contact with conductor 1997, and the next contact to start the sequence over is made by ball Ztll contacting conductor 16%. Following the heretofore described sampling sequence, it will be observed that all 45 contacts are made in of 360 angular rotation of the ball centers, which means that the electrical rotation of the commutator is seven times the actual mechanical rotation. All that is necessary at this time to obtain 900 data samples per second is for the balls Zlli through 2&7 to make twenty electrical revolutions per second. To obtain this, the appropriate mechanical drive must be obtained so that the ball centers travel 360 in 0.35 second. Stated differently, as ball 201 rolls around the periphery of ring 7 of 360, it will have just lost contact with conductor liillll and just made contact with conductor 1W8. Likewise, each ball 2G1 through 237 will have made one contact during the of 360 rotation.

In FIGURE la, the electrical numbering sequence of contacting the balls goes mechanically counterclockwise l-t fil to Nil-3 to will, which means that the next conductor in the counterclockwise mechanical sequence is always electrically the seventh conductor contacted when seven balls are utilized.

It should be appreciated that if five balls instead of seven were used, the first ball would make contact, for instance, to the first conductor of the electrical sequence and then the sixth conductor of the electrical sequence. Under this condition, the number of conductors would arrest)? remain at 45 with 8 spacing; however, the size of the ball would have to be changed so that a contact would be made for each /5 angular rotation of the first ball between the first and the sixth electrical conductors. Gf course, the angular rotation of each ball is the same since the balls are rotated concurrently.

In the counterclockwise mechanical sequence, the first ball would contact the first electrical conductor, and then after 8 of rotation, the first ball would contact the sixth electrical conductor in the electrical sequence even though it is the next mechanical conductor in the counterclockwise mechanical sequence.

It should be appreciated that the above detailed specific embodiment is described with respect to FIGURE in; however, the principles disclosed clearly relate to all the embodiments.

FIGURE 3 shows, as an alternative embodiment of the present invention, a multiple channel commutator utilizing a rolling contact-type structure. The commutator is comprised of barrel-shaped rollers held in a race defined between a freely rotatable conducting collector shaft 26 and a stationary nonconducting ring 27. An inner roller race 28 is formed on the peripheral surface of the shaft 26, and an outer roller race 29 is formed on the inner peripheral surface of the stationary nonconducting ring 27. The inner race 28 is formed in the shaft 26 with shoulders 36 which contact with the ends of the rollers 25. The stationary nonconducting ring 27 has shoulders 31 which also contact with the ends of the rollers 25. The races 28 and 23 in shaft 26 and ring 27, respectively, are shaped to insure proper positioning of the rollers 25. Screw 32 is used to mount the nonconducting ring 27 to a stationary bracket 33.

Each of the barrel-shaped rollers 25 consists of a series of conducting disks 34, 35, 36 and 37 insulated from each other by disks 38, 39 and 40 of insulating material. he multiple channel commutator is made possible because the barrel-shaped rollers 25 make contact with the conducting collector shaft 26 and nonconducting ring 27 over a wide area.

Four rows of conductors 41, 42, 43 and 44 are imbedded in the stationary non-conducting ring 27 and distributed around the entire inner periphery of the nonconducting ring 27. The four rows of imbedded conductors 41, 42, 43 and 44 are positioned to make electrical contact with the conducting disks 34, 35, 36 and 37, respectively, of the rollers 25. Conductor leads .5, 4-6, 47 and 43 are connected to the imbedded conductors 41, 42, 43 and 44, respectively. Each of the four rows of conductors 41, 42, 43 and 44, in combination with each of the four conducting disks 34, 35, 36 and 37, serves as a single channel commutator.

The conducting collector shaft 26 shown in FIGURE 3 has an axial bore extending from one end through to the other end. The left-end portion of the shaft 26 consists of a series of conducting disks 54, and 56 insulated from each other by disks 57, 58 and 59 of insulating material. The conducting disks 54, 55 and 5-6 of the laminated shaft 26 are radially aligned with and in electrical contact with the conducting disks 34, 35 and 36, respectively, of the rollers 25. The insulating disks 57, 58 and 59 of the laminated shaft 26 are also radially aligned with and in contact with the insulating disks 33, 33 and 4%, respectively, of the laminated. rollers 25. The right-end portion of the shaft 26 consists of a series of conducting disks 66, 61, and 62 insulated from each other by insulating disks 63, 64 and 65. The middle portion of the laminated shaft 26 consists of a common conducting annulus 66, which is in electrical contact with the conducting disks 37 of the rollers 25 and one row of ball bearings 67 positioned to the right in FIG- URE 3. Wires 6%, 69 and 7d are used to connect electrically the conducting disks 54, 55 and 56 at the letend portion of the shaft 26 with the conducting disks 6%, 61 and 62 at the right-end portion of the shaft 26, wire 6S connecting the outer disks 54 and 62, intermediate disks 55 and 61 connected by wire 69, and inner disks 56 and 6% connected by wire 70. The wires are connected to the conducting disks by any conventional means, such as soldering.

The outer surface of the conducting collector shaft 26 defines four inner races 71, 72, 73 and 74 axially spaced to the right of inner race 28 as viewed in FIGURE 3. Inner races 72, 73 and 74 are formed on the conducting disks 6%}, 61 and 62, respectively. Inner race 71 is formed on the right-end portion of the common conducting annulus 66. Rows of ball bearings 67 are positioned in the races 71, 72, 73 and 74 and a laminated conducting ring 75 concentrically encompasses the balls 67 and shaft 26. The balls 67 are also received in outer races 83, 84, and 86 defined by the inner peripheral surface of the ring 75. The laminated conducting ring 75 consists of a series of conducting disks 76, 77, 78 and 79 electrically separated by insulating disks 80, 81 and 82. Outer races 83, 84, 85 and 86 are formed on the conducting disks 76, 77, 78 and 79, respectively. The insulating disks 80, 81 and S2 of the ring 75 are radially aligned with insulating disks 63, 64 and 65 of shaft 26. An insulating layer 87 is interposed between ring 75 and bracket 33 to isolate these elements electrically. Takeoff contact wires 89, 9t), 91 and 92 are positioned to make electrical contact with conducting disks 76, 77, 78 and 79, respectively, of the ring 75 by passing them through the bracket 86 and insulating layer 87, and imbedding them in the conducting disks 76, 77, 78 and 79. The contact wires 89, 9d, 91 and 92 are insulated electrically from bracket 88 by insulating material 93, 94, 95 and 96, respectively. The conducting ring 75 is made stationary by attaching it to the bracket 88. A threaded bolt is passed through bracket 83 and insulating layer 87, and is screwed in the ring 75 (for simplicity, the bolt is not illustrated). A sleeve electrically insulates the bolt from bracket 83. The bracket 88 is made stationary by any conventional means.

The laminated rollers 25, as shown in FIGURE 3, are mounted to rotate similar to the balls in FIGURE 2. The rollers 25 have holes extending completely through the conducting disks 34, 35, 36 and 37 and the nonconducting disks 38, 39 and 40. The left ends of studs 49 are inserted in the holes in the laminated rollers 25. An annulus 5t), which surrounds the freely rotatable collector shaft 26, has holes located therein. The right ends of insulator studs 43 are inserted in the holes in the disk 5t). Collars 51 are mounted on studs 49 to prevent the studs 49 from sliding out of the holes in the rollers 25 and the annulus 5h. The annulus 50 has gear teeth 52 on its outer periphery to mesh with spur gear 53, which is driven by an electric motor, or any other suitable means via shaft 127.

When the annulus 56 is rotated by the spur gear 53, the rollers 25 and the collector shaft 26 rotate due to the interference or frictional fit. The four conducting disks 34, 35, 36 and 37 of the rollers 25 move and sample the four rows of embedded conductors 41, 42, 43 and 44, respectively, in time sequence by making rolling contact with the four rows of embedded conductors 41, 42, 43 and 44. The disks 34, 35, 36 and 37 are mounted on studs 49 and attached to annulus 5% to ensure that they are maintained in proper spatial relationship. This will also ensure that the disks 34, 35, 36 and 37 of the rollers 25 will make contact with only one conductor in each row of the conductors 41, 42, 43 and 44, respectively, at any one moment. The four conducting disks, 34, 35, 36 and 37 of the rollers 25 provide a four-channel commutator in place of the single channel commutator shown in FIGURE 2. Singlechannel operation consists of sampling the information present on the conductors 41 as electrical signals by the disks 34 in time sequence, and transmitting via conducting disk 54, wire 68, conducting disk 62, balls 67 and ring '75 to take-off conductor 92. The four channels operate in the same manner. It is not my intention to limit the principles of this invention to a four-channel commutator, but it may have any suitable number of channels depending upon its application.

It is appreciated that the apparatus can be modified so that the conducting rollers 25 are not driven directly. Appropriate drive means may be used to rotate the laminated collector shaft 26 by having gear 53 mesh with an insulator ring gear fixed to the laminated collector shaft 2d. The rollers 25 will rotate due to the interference or frictional fit. A suitable means can be used to remove the electrical information from the collector shaft 26.

FIGURES 4 and show an alternative embodiment of a single-channel commutator. Apparatus used for this embodiment is less expensive and less complicated than the apparatus used for the single-channel commutator shown in FIGURE 1. The commutator is comprised of balls ltltl held in a race defined by a freely rotatable conducting shaft fill and a stationary ring 1632. The ring 192 consists of a nonconducting material having a curved conducting bar Th3 embedded in a portion thereof. The embedded conducting bar has a curved surface, and follows the contour of the inner surface of ring Th2. The conducting bar MP3 serves as the collector and can be of any suitable conducting material. Using the conducting bar 1% as the collector enables many parts of the apparatus shown in FIGURE 1 to be eliminated. This embodiment provides an inexpensive and simple single-channel commutator.

A plurality of conductors 194 having conductor leads 1% connected thereto are embedded in the stationary ring 192. The length of the curved collector bar 163 shown in FIGURE 4 is equal to one-quarter of the circumference of the ring 192. It is appreciated that the minimum length of the bar 193 must be equal to the distance between the centers of two adjacent balls 1% so that at least one contact ball will be making electrical contact with the curved collector bar at all times. A single take-off conductor 1% is connected to the outer surface of the curved collector bar 1'93 by any suitable means. Ring 102 is mounted to a stationary bracket 111 by means of screw 114.

FIGURE 5 shows the conducting balls 100 rotatably mounted by means of insulator studs 107, which are attached to an annulus 108. A collar 109 is mounted on each insulator stud 107. Gear teeth 110 on the periphery of annulus N8 mesh with a spur gear 112, which is driven by a motor, or any other suitable means via shaft 113.

The operation of the apparatus shown in FIGURE 4 is similar to that shown in FIGURE 1. When the disk Tilt"; is rotated by spur gear 112, the balls 1% and shaft fill rotate due to the interference or frictional fit. The balls 1% each make contact with only one conductor 164 at any one moment. Thus, the information present on the conductors 164 as electrical signals is sampled by the balls 1% in sequence, and transmitted via shaft Till, contact balls ltltl, and bar 163 to take-off conductor 196.

It is not my intention to limit the embodiment shown in FIGURE 4 to the single-channel commutator, but it may be converted to a multi-channel commutator by appropriate changes.

The apparatus in FIGURE 4 can be modified so that the conducting balls liitl are not driven directly. Appropriate drive means can be used to rotate the shaft Trill by having gear 112 mesh with a ring gear fixed to the shaft 191. This will cause the balls ltltl to rotate due to the interference or frictional fit.

The single-channel commutator shown in FIGURE 1 can be modified so that the relative positions of the pickup conductors and take-off conductor are reversed. As modified, the conducting balls are held in a race defined between a stationary non-conducting shaft and a freely rotatable conducting collector ring. The stationary non conducting shaft has an axial bore with its ends open. Conductors with conductor leads connected thereto are embedded in the stationary nonconducting shaft and distributed around the outer periphery of the shaft, exposed in the inner ball race. The surfaces of the conductors follow the contour of the inner ball race defined on the periphery of the shaft. The conductor leads extend through the axial bore of the shaft to one of its open ends. The freely rotatable conducting collector ring has a race formed on both its inner and outer peripheries. The conducting balls are mounted to rotate freely by suitable means, such as that shown in FIGURE 1. Ball bearings are positioned in the race on the outer periphery of the freely rotatable collector ring, and a stationary conducting disk encompasses the ball bearings and the collector ring. The stationary conducting disk is attached to a bracket, which is made stationary by suitable means. An insulating layer is interposed between the stationary disk and the bracket to isolate these elements electrically. A single take-off conductor is connected to the stationary conducting disk by suitable means. Thus, information present on the conductor distributed around the outer peripheral surface of the shaft is sampled by the conducting balls in sequence, and transmitted via the freely rotatable collector ring, the ball bearings and the stationary disk to the take-off conductor. The modified arrangement for the single-channel commutator is also adaptable to multi-channel operation using the teachings of FIGURE 3. The key feature of this arrangement is that all parts are positioned both coaxially and concentrically.

Although the present invention has been shown and described in the terms of a specific preferred embodiment, changes and modifications which do not depart from the inventive concepts taught herein will suggest themselves to those skilled in the art. Such changes and modifications are deemed to fall within the scope and contemplations of the inventions.

What is claimed is:

1. An electromechanical commutator comprising a stationary electrically insulating ring, an electrically conducting shaft, said ring and said shaft being arranged concentrically and defining opposed radially aligned circular races concave in cross section, a disk, studs mounted on said disk and peripherally spaced thereabout, electrically conducting balls mounted on said studs and positioned in said circular races, a plurality of electrical contacts mounted in the circular race of said electrically insulating ring and peripherally spaced therearound, and means to drive said disk to move said balls around the circular races whereupon said balls engage said electrical contacts and transmit electrical signals thereon to said electrically conducting shaft.

2. An electromechanical commutator comprising a stationary electrically insulating ring, an electrically conducting shaft, said electrically insulating ring and said electrically conducting shaft being arranged concentrically and defining first aligned circular races, a disk encompassing said electrically conducting shaft, studs mounted on said disk and peripherally spaced thereabout, electrically conducting balls mounted on said studs and positioned in the first circular races, input signal conductors embedded in said electrically insulating ring and distributed peripherally about the first circular race, an electrically conducting ring concentrically encompassing said electrically conducting shaft, said electrically conducting ring and said electrically conducting shaft defining second aligned circular races, rolling electrically conductive bodies positioned in the said second circular races, and means to drive said disk to move said balls around the first circular races whereupon said electrically conducting balls make contact with said embedded conductors and transmit electrical signals thereon to said electrically conducting shaft.

3. A multiple channel electromechanical commutator comprising a stationary electrically insulating ring, a shaft divided axially into first and second parts, said electrically insulating ring and said first part of said shaft arranged concentrically and defining first aligned circular races, a disk, studs mounted on said disk peripherally spaced, rollers mounted on said studs and positioned in the first circular races, said first part of said shaft and said rollers divided into axially spaced, aligned, electrically conductive sections, axially spaced rows of peripherally spaced electrical contacts embedded in the first circular race of said electrically insulating ring, each of said rows cooperating with aligned electrically conductive sections of said rollers, an electrically conducting ring concentrically encompassing the second part of said shaft, said electrically conducting ring and said second part of said shaft defining second aligned circular races, rolling conductive bodies positioned in the second circular races, said electrically conducting ring and said second part of said shaft divided into axially spaced, aligned, electrically conductive sections, electrical means interconnecting the electrically conductive sections of said first and second parts of said shaft, and means to drive said disk to move said rollers around the first circular races whereupon each electrically conductive section of each said roller makes contact with one row of said embedded electrical contacts to transmit electrical signals thereon to one electrically conductive section of said electrically conducting ring via said first part of said shaft, said electrical means, said second part of said shaft and said rolling conductive bodies.

4. An electromechanical commutator comprising a sta tionary electrically insulating ring, an electrically conducting shaft mounted for rotation, said electrically insulating ring and said electrically conducting shaft arranged concentrically and defining opposed radially aligned circular races concave in cross section, a disk, studs mounted on said disk peripherally spaced, electrically conducting balls mounted on said studs and positioned in the circular races, an electrically conducting strip and a plurality of electrical contacts mounted in the circular race of said electrically insulating ring peripherally spaced therearound, and means to drive said disk to move said balls around the circular races so that said balls engage said electrical contacts and said conducting strip and transmit electrical signals from said electrical contacts to said electrically conducting shaft whereupon the electrical signals are retransmitted to said electrically conducting strip.

5. An electromechanical commutator comprising an electrically insulating part, an electrically conducting part, said insulating and conducting parts being arranged concentrically with respect to each other and defining opposed radially aligned continuous circular races concave in crosssection, an electrically conducting strip mounted in the race of said electrically insulating part, thereby to establish an additional electric path from said electrically conducting part to said electrically conducting strip, a plurality of electrically conducting elements each defining a rolling axis and being circular in cross-section normal to said axis, said elements being positioned in said races, a plurality of electrical contacts mounted in the circular race of said electrically insulating part and peripherally spaced therearound, and means for moving said elements around the circular races, whereby said electrically conducting element engages said electrical contacts to establish an electric path from said electrical contacts to said electrically conducting part.

6. The electromechanical commutator of claim wherein said means for maintaining said elements in spaced relationship with respect to each other includes means having projections thereon for mounting said elements.

7. The electromechanical commutator of claim 5 wherein said last mentioned means includes a disk having studs peripherally spaced therearound, and wherein said elements are mounted on said studs.

8. An electromechanical commutator comprising an electrically insulating part and an electrically conducting part concentrically arranged and defining opposed radially aligned circular races concave in cross-section, a disk, studs mounted on said disk and peripherally spaced therearound, electrically conducting balls mounted on said studs and positioned in said races, a plurality of electrical contacts mounted in the circular race of said insulating part and peripherally spaced therearound, and means for moving said balls around said races, whereby said balls engage said contacts to establish an electrical path from said contacts to said conducting part.

9. An electromechanical commutator comprising a first electrically conducting part and an electrically insulating part concentrically arranged and defining aligned first circular races, a disk, studs mounted on said disk and peripherally spaced therearound, electrically conducting balls mounted on said studs and positioned in said first circular races, a plurality of electrical contacts mounted in the first circular race of said electrically insulating part, a second electrically conducting part and said first electrically conducting part concentrically arranged and defining aligned second circular races, electrically conducting bodies positioned in said second circular race, and means for moving said balls around said first circular race, whereby said balls engage said contacts to establish an electrical path from said contacts to said second electrically conducting part.

10. An electromechanical commutator comprising an electrically insulating part, an electrically conducting part, said insulating and conducting parts being arranged concentrically and defining opposed radially aligned circular races concave in cross-section, a plurality of elements each defining a rolling axis and being circular in crosssection normal to said axis, said elements being positioned in said races, at least one of said elements being electrically conductive, a plurality of electrical contacts mounted in the circular race of said electrically insulating part and peripherally spaced therearound, an electrically conducting member concentrically encompassing said electrically conducting part, said member and said electrically conducting part defining aligned circular races, rolling electrically conductive bodies positioned in the circular races defined by said member and said electrically conducting part, and means for moving said elements around the circular races defined by said electrically insulating part and said electrically conducting part, whereby said conductive element engages said electrical contacts and an electrical path is established from said contacts to said electrically conducting member.

References Cited in the file of this patent UNITED STATES PATENTS 2,133,980 Fowler Oct. 25, 1938 2,454,524 Rietschel Nov. 23, 1948 2,754,386 Gaylord July 10, 1956 2,825,768 Beck Mar. 4, 1958 2,856,472 Humphries Oct. 14, 1958 FOREIGN PATENTS 28,834 Great Britain 11913 224,770 Great Britain Nov. 20, 1924 596,094 Great Britain Dec. 29, 1947 276,195 Germany June 13, 1913 673,791 France Oct. 14, 1929 

1. AN ELECTROMECHANICAL COMMUTATOR COMPRISING A STATIONARY ELECTRICALLY INSULATING RING, AN ELECTRICALLY CONDUCTING SHAFT, SAID RING AND SAID SHAFT BEING ARRANGED CONCENTRICALLY AND DEFINING OPPOSED RADIALLY ALIGNED CIRCULAR RACES CONCAVE IN CROSS SECTION, A DISK, STUDS MOUNTED ON SAID DISK AND PERIPHERALLY SPACED THEREABOUT, ELECTRICALLY CONDUCTING BALLS MOUNTED ON SAID STUDS AND POSITIONED IN SAID CIRCULAR RACES, A PLURALITY OF ELECTRICAL CONTACTS 